SLAE: Assignment 7 of 7

Assignment #7:
- Create a custom crypter like the one shown in the course
- Free to use any existing encryption schema like RC4 or AES
- Can use any programming language

My encoder will use the small but strong encryption algorithm TEA to encode the shellcode. The shellcode is the execve code used in assignment 4:
# execve('/bin/ls') - shellcode size is 25 bytes
shellcode = ("\x31\xc0\x50\x68\x2f\x2f\x6c\x73\x68\x2f\x62\x69\x6e\x89\xe3\x50\x89\xe2\x53\x89\xe1\xb0\x0b\xcd\x80")

Note: I used the following TEA key: [0x90909090, 0x90909090, 0x90909090, 0x90909090]

Note:We test the code works:

Original_shellcode = (

Encrypted_shellcode = (

Note: We test that the program works:

Decrypting Encrypted_shellcode now...
Running decrypted shellcode now...

Note: The program correctly executes execve('/bin/ls') and lists the directory structure